Conversations makes it very easy to create an account on the conversations.im server. Using that server comes with an annual fee of 8 Euro after a 6 month trial period. However Conversations will work with any other XMPP server as well. A lot of XMPP servers are run by volunteers and are free of charge.

XMPP Features:

Conversations works with every XMPP server out there. However XMPP is an extensible protocol. These extensions are standardized as well in so called XEP’s. Conversations supports a couple of those to make the overall user experience better. There is a chance that your current XMPP server does not support these extensions. Therefore to get the most out of Conversations you should consider either switching to an XMPP server that does or - even better - run your own XMPP server for you and your friends.

These XEPs are - as of now:

XEP-0065: SOCKS5 Bytestreams (or mod_proxy65). Will be used to transfer files if both parties are behind a firewall (NAT).

XEP-0163: Personal Eventing Protocol for avatars

XEP-0191: Blocking command lets you blacklist spammers or block contacts without removing them from your roster.

XEP-0280: Message Carbons which automatically syncs the messages you send to your desktop client and thus allows you to switch seamlessly from your mobile client to your desktop client and back within one conversation.